The funny thing is that any immunity boost imparted by infection (aka natural immunity) was made possible by vaccines lessening the severity of infection. If your idea of natural immunity is purely infection without any sort of vaccination, we'd have been in for much more hurt.
I don't really buy this because my personal experience of infection without vaccination wasn't so terrible. Same goes for everyone in my household who got covid and wasn't vaccinated, and many other unvaccinated friends who had it. In my view, there wasn't any noticeable difference between vaccinated and unvaccinated friends who got covid...
I think a lot depends on your circles of friends -- if everyone you know is vaccinated, and the news tells you vaccination reduces severity by a noticeable amount, you tend to believe it, because why wouldnt you, if you dont know many unvaccinated people.
But if you know many unvaxed and vaxed people who had the same covid experience, then you're gonna be scratching your head (and rolling your eyes) when you hear the line, "I'm just glad I was vaccinated otherwise it would have been much worse...."
If the vaccine was really such a success, I think people would've noticed a big difference. Maybe that difference existed for the alpha strain, but certainly wasnt there for delta or omicron from what I saw on the ground. Who knows though.